NGHIÊN CỨU TỔNG HỢP VẬT LIỆU AEROGEL TRÊN NỀN GRAPHEN VÀ ỨNG DỤNG ĐỂ XỬ LÝ XANH METYLEN TRONG MÔI TRƯỜNG NƯỚC

Tóm tắt

In this study, we successfully synthesized graphene aerogel (GA) by hydrothermal method followed by
the freeze-drying technique. The structural analysis of the materials obtained by XRD, SEM/EDX, and
FT-IR spectroscopy showed that the GA presented a 3D structure while its precursor was the 2D
material. When graphene oxide (GO) was transformed to GA, the characteristic XRD peak at about 10˚
was completely removed and there were no other significant peaks, indicating that the crystalline
structure of GO was converted to amorphous form of GA. The C/O ratio in GO (1.4/1.0) was
significantly lower than in GA (3.2/1.0). The absorption of methylene blue (MB) in aqueous solutions
by GA was influenced by different parameters such as pH, reaction time, adsorbent load, and initial
concentration of MB. The optimum conditions for the adsorption of MB were 100 mL of 20 mg/L MB
solution, pH11, 100 min adsorption time under atmospheric conditions. In our research, the Langmuir
and Freundlich models received the coefficients of 0.987 and 0.970, respectively, suggesting that
Langmuir isotherm model better described the experimental data compared to Freundlich one.
According to Langmuir isotherm model, the maximum adsorption capacity (Qmax) of GA regarding
MB in solutions was 32.9 mg/g.